Current collector



1., L. WHITTAKER.

CURRENT COLLECTOR.

APPLICATION FILED JULY H.191].

Patented Feb. 21, 1922.

Inward/or: JohwLQT vhi/fiak UNITED STATES PATENT OFFICE.

JOHN L. WHIT'IAKER, OF WINTHROIP, MASSACHUSETTS, ASSIGNOR TO MILLER- TROLLEY SHOE COMPANY, 033 BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

Application filed July 11,

To all whom it may concern:

Be it known that I, JOHN L. lVI-II'LTAKER, a subject of the King of Great Britain, who have declared my intention to become a citizen of the United States, and a resident of Winthrop, in the county of Sulfolk and State of Massachusetts, have invented an Improvement in Current Collectors, of which the following description,in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to current collectors for overhead trolley systems. The particular purpose is to provide an improved device of that type wherein the contact member is a shoe which slides along the trolley wire.

My invention will best be understood by reference to the following description of an illustrative embodiment thereof, shown in the accompanying drawings wherein:

Fig. 1 is a side elevation of the collector in operative position on the trolley wire;

Fig. 2 is a central longitudinal section of the same, the parts being in the position they assume when not in contact with the wire; and

V Fig. 3 is a section on the line 3--3 of Fig. 1. v

In the drawings I have shown the collector member carried by the tubular'cap 5, adapted to be fitted to the end of a trolley pole which is elevated toward the trolley wire 10 by any of the usual forms of spring gear. Formed on or carried by this cap is a harp 7 which in the present embodiment includes side plates 9 and a bottom plate 11 integral with the side plates and closing the space between them, the bottom plate serving to prevent the entrance of the trolley wire between the side plates of the harp. In the form here shown the bottom plate 11 is extended as at 13 to further guard the shoe mounted in the harp, as will hereinafter more clearly appear. The harp may be provided with a loop 15 to receive the usual controlling rope.

In the form of the invention here illustrated the harp 7 is separate from the cap and mounted thereon for limited trans verse swiveling movement. For this purpose the harp 7 with the cap 5 may be provided with cooperating hinge knuckles 17 adapted to be joined by a ,pintle pin 19 which will be substantially vertical in the Specification of Letters Patent.

Patented Feb. 21, 1922.

1917. Serial No. 179,974.

normal position of the collector. The knuckles 17, as indicated in Fig. 1, are not round but spaces 21 are provided which permit the two parts to swivel, this swiveling movement being limited by the contact of the corners of the knuckles with the surfaces facing them. This swiveling of the collector shoe permits the same to adapt itself to the trolley wire in passing around curves or the like. This action is particularly desirable in the case of a sliding contact collector since it has an extending bearing 011 the wire in stead of what is substantially a point hearing as in the case of wheels.

The collector shoe proper is denoted gen erally by the numeral 28 and I shall for the moment postpone the detailed description of its construction until after I have described the manner in which it is mounted in the harp. Extending between the side plates of the harp is a journal 25 for the shoe which may conveniently take the form of a short tubular member whose ends are flush with the outer surfaces of the plates 9. The journal 25 may be secured in position by a cotter 27. The shoe 28, as I indicated at the beginning of this description, is a sliding contact shoe, it is mounted for limiting swinging movement about a horizontal axis and is, so to speak, biased. In other words, the rear or following end of the shoe normally tends to tip upwardly so as to resist the frictional drag of the trolley wire to. As seen from Fig. 1, the trolley wire depresses the shoe to a horizontal position and suitable means such as the spring 29, seen in F ig, 2,. interposed between the bottom plate 11 of the harp and the shoe normally tends to force the shoe to the position shown in Fig. 2. The frictional drag of the trolley wire tends to throw the forward or leading end of the shoe upwardly, but the action of the spring 29 resists this and holds the shoe horizontal in proper position for contact I with the wire. A slight rocking movement I of the shoe is provided which makes for even wear.

By referring to Fig. 2 it will be noted that the spring 29 is housed by the bottom plate 11 and side plates 9 of the harp. To provide good conducting qualities a flexible .bond 31 which may take the form of braided copper tape or the like, may also be housed in this space and secured atone end to the shoe 28 as shown and at the other end to the harp.

Conveniently it may be secured to the pintle pin 19 as shown, whereby a good connection to the cap 5 and thence to the motors of the car is provided for.

I shall next describe in detail the construction of the shoe 23. As shown by Figs. 1 and 3 this shoe is, roughly speaking, T- shaped in cross section, and embodies a tread member 33 corresponding to the cross bar of the T and the web member 35 corresponding to the stem. The tread member 33 (see Fig. 2) has a central substantially fiat longitudinal part 37 merging into downwardly curved ends 39 and has lateral longitudinal flanges ll providing between them a trolley receiving groove for the wire w, as best seen in Fig. 3. The width of the tread member 33 is preferably greater than that of the harp 7, as clearly seen in Fig. 3, so that the harp is protected by the tread member and there is no danger of the trolley wire coming in contact with the sides of the harp and catching therein to break it or are weld any portions thereof.

It will be understood that the wear on the collector is concentrated upon the shoe and in particular upon the tread member there of. This tread member is therefore preferably formed of suitable hardened steel, such as vanadium steel. It will be clear that if the remainder of the device can be made of cheaper metal and the tread member changed when worn a considerable economy may be efl'ected. In the present instance I provide for this by making the web portion 35 of the shoe separate from and readily detachable from the tread portion. For this purpose the tread member 33.is provided with a central longitudinal groove 43 in its under surface, in which the web member 35 is adapted to fit and preferably this groove is formed as shown, by two spaced flanges 45. The web member 35 may be inserted in the groove 43 and'secured in position by rivets 47 passing through the flanges and headed over on the same. When the tread member is worn it can be readily removed by cutting off the heads of the rivets and punching them out and in this connection it may be noted that the body portion of the tread member over hangs the heads of the rivets and prevents the trolley wire from cominginto contact with them in such manner that they might be are welded in position and the two parts thus permanently fixed together. To insure good contact between the tread member and the web member the groove 43 is prefer abl tapered and the end of the web similarly tapered so as to provide a tight fit between the two members.

The web member 35 extends between the side plates 9 of the harp and is pivoted thereto, the tread member 33 overlying the tops of the same. The member 35 may be provided with a boss .9 forming a hub which will give an extended bearing for the shoe and the journal 25 extends through this hub,

preferably with the interposition of a suitable lubricating bushing 50.

To strengthen the web member and to provide a bearing for the spring 29 it may have basal flanges 51 best seen in Fig. 3. This flange portion may be extended beyond the main body of the web portion to form a tongue 53 which provides a convenient place for the attachment of the bond 31. i

The extension 13 of the bottom plate 11 of the shoe already referred to, extends up. wardly toward the rear end of the shoe and acts as a guard to prevent overhead wires from catching underneath the rear end thereof.

While the wire receiving groove of the shoe may take any convenient form, preferably I make the bottom substantially fiat in cross section, as seen in Fig. 3, and considerably wider than the wire w which it is adapted to receive. It may be filleted at the sides as indicated at 55, the fillets merging into the flaring inner surfaces of the flanges 11 The wire is thus permitted a certain amount of lateral play and may at different times rest at different angles across the groove, which will distribute the wear on the tread member 33 and delay the wearing of a channel therein. As is well known, the sections of wire of an electric trolley line are frequently joined by metal clamps embracing the opposed en s of the wire sections. As the surface of the collector member through wear approximates the. form of the wire, a wearing edge will be formed thereon which will come in contact with these clamps and destroy them. By providing for distribution of wear over the surface of the tread 33 a longer life is assured the shoe before it is necessary to renew thetread because of danger to the clamps.

An important feature of the construction described is that no bolts are utilized to hold the parts to ether by mechanical clamping pressure. 'I he use of bolts is ob jectionable because they may loosen and because they form projections which will catch overhead wires and are likely to be welded in place, preventing dismounting of the parts. The shoe shown avoids the use of bolts but provides a construction with a. renewable tread member, which may be easily changed and this member is a solid integral structure presenting no joints to the trolley wire. The structure as a whole has a minimum number of joints, is one in which all the joints may readily be made tight to stay tight and one in which they are all well protected.

Having described in detail the embodi ment of myinvention which I have chosen for purposes of illustration, the features which I regard as new and desire to secure by Letters Patent I shall define in the following claims:

1. An overhead device of the class described comprising a shoe of general T section including a grooved member for sliding contact with the trolley wire and a central longitudinal web beneath said member, a forked harp, a pivot member mounted across the fork, said web being journaled on the pivot member.

2; An overhead device of the class described comprising a shoe of general T section including a grooved member for sliding contact with the trolley wire and a central longitudinal web beneath said member,

a forked harp, a pivot member extending across said fork and having its ends bearing in the arms thereof and terminating substantially flush with the outer faces thereof, said web being journalled on the pivot member.

3. An overhead device as defined in claim 1 in which the grooved contact member is wider than and overhangs the harp. I

4. An overhead device of the class described comprising a forked harp, a web member snugly received between the arms of said harp and pivoted therein and a removable tread member grooved for sliding con tact with the trolley wire and having a longitudinal groove on the under side in which said web member is received and being of a width to overhang the arms of the harp.

5. An overhead device of the kind described comprising a contact shoe having a tread portion with an exterior trolley receiving groove and a depending web portion, a harp comprising an integral bottom portion and side plates between which said web is pivoted and a spring housed in said harp and normally tilting upwardly the rear end of the shoe.

6. In an overhead device of the kind described a forked harp, a contact member having a tread and a depending web pivoted between the arms of said harp, said web having a basal flange extended beyond the web to provide a tongue and a conducting bond secured to said tongue and to said harp.

7. In an overhead device of the kind described a forked harp, a contact member having a tread and a depending web pivoted between the arms of said harp, said web having a basal flange and a spring interposed between said harp and flange.

In testimony whereof, I have signed my name to this specification.

JOHN L. WHITTAKER. 

